This invention relates to jigsaw puzzles for use by young children as an aid to learning elementary arithmetic, i.e., addition, substraction, multiplication and division.
A number of puzzle devices for teaching elementary mathematics to young children have been proposed.
U.S. Pat. No. 4,360,347 describes a mathematical educational game device. The embodiment illustrated in FIGS. 1-3 is in the form of a circular puzzle having a plurality of pieces 15. The puzzle has no center piece (being open in the middle) and a plurality of wedge-shaped puzzle members 15. Numbers or arithmetic operators are printed on one side of the puzzle members 15. Each radial column is comprised of four pieces, the outer row containing a number, the next inner row containing an arithmetic operator, the next inner row containing the question number and the inner row containing the answer number. Problems can also be similarly presented and solved within each circumferential row.
U.S. Pat. No. 2,875,531 describes an educational device of interlocked puzzle pieces 15. A frame 10 is comprised of frame members 11 enclosing a front transparent window 12 set in slots 13. A rear cover 16 is inserted into slots 17. The puzzle pieces 15 are put together following the instructions contained on the rear cover 16 of frame 10, reading down the left column first and then moving down the right column. The puzzle pieces 15 are put together moving always in a clockwise direction, forming the border first. Where, for example, the instructions call for xe2x80x9c1+1xe2x80x9d, the student places the puzzle piece 15 containing the number xe2x80x9c2xe2x80x9d. When the puzzle pieces are put together properly, a picture 14 is formed on the side of the puzzle opposite to the answer side of pieces 15. It does not appear that the pieces 15 could be interlocked together other than in the correct way. The picture 14 is not used to check the answers selected; it is merely the product of putting the puzzle together as in any jigsaw puzzle.
U.S. Pat. No. 4,422,642 describes an educational puzzle for various skills, including mathematics. The puzzle, when assembled, is rectangular in shape. In the embodiments illustrated in FIGS. 1 and 2, there are three rows and three columns of interlocking puzzle pieces containing arithmetic questions and answers in both the horizontal rows and vertical columns. In the embodiment of FIG. 2, the three columns are color coded. The pieces can be interlocked in only one way, i.e., they cannot be assembled to proved wrong answers.
U.S. Pat. No. 5,743,741 describes a math jigsaw puzzle. The puzzle, when assembled, is rectangular in shape. Although several embodiments are described, they all operate on the same principal as that shown in FIGS. 1A-1L in which one starts with a center piece 24 which has a central number in large print surrounded by four equally spaced numbers in smaller print (see FIG. 1-F). One then interlocks a piece 30 to the center piece 24 to solve the problem presented by the central number and adjacent surrounding number of the center piece, as shown in FIG. 1-G. Each added piece 30 presents a new math problem which is solved by interlocking a further solution piece, as shown in FIGS. 1-H through 1-L. The pieces can be interlocked in only one way, i.e., they cannot be assembled to provide wrong answers.
A problem with all of these prior art puzzles is that none of the them can have their pieces interlocked together to provide a wrong answer and a way to clue the child that his/her answer is wrong, thereby causing the child to re-think and re-work his wrong answer. It is an object of the present invention to provide such a math teaching puzzle.
The present invention relates to four sets of jigsaw puzzles designed to assist young children in learning elementary arithmetic. One of the four sets is designed to aid in learning elementary addition, one set for elementary subtraction, one set for elementary multiplication, and one set for elementary division. Each set is comprised of a plurality of puzzles of varying complexity. Preferably a set is comprised of ten puzzles which provides a separate puzzle for arithmetic questions involving operating numbers selected from 1 through 10.
Each puzzle is circular and essentially two dimensional. Each puzzle is comprised of a center piece, four middle ring question pieces, and twelve outer ring answer pieces.
One side of each puzzle contains the arithmetic question and answer pieces and the other side forms a picture when the question and answer pieces are put together correctly. The printed pattern forming the background to the question side of the puzzle is preferably different for each puzzle so pieces cannot be inadvertently mixed up.
Each puzzle comes in a container that includes a transparent tray and transparent cover. The transparent tray is for assembling the pieces of the puzzle. The transparent cover is adapted to be snapped into place over the tray and allow the container to be turned over to view the picture side and determine if the picture is either (1) assembled properly (which means that all of the arithmetic questions have been answered correctly) or (2) assembled improperly (which means that some or all of the arithmetic questions have not been answered correctly).
The circular center piece contains twelve evenly spaced apart and different numbers (xe2x80x9coperandsxe2x80x9d) located adjacent its periphery. The center piece has a peripheral keying projection adjacent one of the operand numbers. The four middle ring question pieces have concave inner sides that constitute a chord having a length that is one fourth the circumference of the circular center piece. The concave inner sides are adapted to matingly fit against the outer periphery of the center piece, with the concave inner side of one of the four pieces (the xe2x80x9ckeystone piecexe2x80x9d) having a keying recess adapted to receive the keying projection extending from the center piece. The sides of the four middle ring question pieces have convexities (tabs) and concavities (recesses) of varying shapes with the tabs of one piece being adapted to be interlocked to a mating recess of an adjacent piece. Thus, the keystone piece fits at only one location adjacent the center piece (with the center piece keying projection being received into the mating keying recess of the keystone piece) while the user needs to place the other three question pieces in specific locations so that the sides of adjacent pieces interlock.
Each of the question pieces have arithmetic questions located radially adjacent each of the operand numbers located on the center piece. The arithmetic questions include an operator sign (+, xe2x88x92, xc3x97, or ÷) followed by an operator number (preferably selected from 1 through 10) and an equal (=) sign. For each puzzle the arithmetic questions are all identical. For example, all of the arithmetic questions appearing on the question pieces of one puzzle in the addition set will contain the math question xe2x80x9c+1=xe2x80x9d, which questions are located radially adjacent the operand numbers on the center piece.
The outer edge (periphery) of each of the four question pieces contain three identical convex tabs extending therefrom, each tab being an identical arc of a circle.
The twelve outer ring answer pieces are identical in shape, with a concave inner edge (recess) adapted to interfit with each and every one of the convex tabs of the question pieces. Thus, the user must interfit the concave recess of the answer piece to the convex tab of the question piece that the user believes supplies the correct answer. For example, if the center piece had the operand number xe2x80x9c11xe2x80x9d followed by the arithmetic question xe2x80x9c+1xe2x80x9d radially adjacent on the question piece, the correct answer piece would be the one having the number xe2x80x9c12xe2x80x9d located thereon. However, since the outer ring answer pieces are all identical in shape, it is possible to interfit an outer ring answer piece containing the wrong answer to the arithmetic question located on the question piece.
After the child has interfit all of the puzzle pieces together, he/she can snap the transparent container cover onto the transparent container tray and turn the puzzle container over to see if the picture on the other side is correct. If correct, it means that the user has selected all of the correct answers to the questions. If the picture is not correct, it means that the user has selected two or more wrong answers.